Conventional motorcycle handbrake assemblies comprise a brake lever which is pivotally mounted on the handlebar, and spaced a relatively small distance apart from the handlebar. The motorcycle brakes are actuated by an operator pulling on the brake lever in a direction tending to move the brake lever toward the handlebar, closing the space between the brake lever and the handlebar. On a conventional motorcycle, the throttle is actuated by means of a cylindrical control member or throttle grip which encircles a portion of the handlebar and which is located proximate to the brake lever.
The conventional handbrake assembly is subject to numerous disadvantages included among which are the following. In the normal mode of operation of the conventional handbrake assembly, the operator keeps his hand on the throttle grip with his fingers and thumb encircling the throttle and the operator rotates the throttle grip to achieve the desired operating speed. To effect a braking action, the operator conventionally straightens his fingers, reaches for and grasps the brake lever with his fingers and with his thumb still encircling the throttle grip, or the portion of the handlebar immediately adjacent to the throttle grip, moves his fingers toward his thumb, thereby squeezing the brake lever toward the throttle grip and actuating the brakes.
The need for the operator to effect the separate actions of straightening his fingers, reaching for the brake lever, grasping the brake lever and squeezing the brake lever toward the throttle grip inevitably causes a time delay which can adversely impact the overall safety of the motorcycle vehicle.
In an effort to overcome this reaction time problem, operators often resort to the expedient of leaving two fingers on the brake lever at all times and operating the throttle with the remaining three fingers. This result is the problem of trying to apply sufficient force in a relatively brief period to actuate the brake system. In addition, the brake lever, when depressed, can pinch the fingers holding the throttle grip. The need to constantly stretch two fingers to grasp the brake lever can also result in operator fatigue and a reduction in control over the handlebars and steering efficiency.
The initial spacing between the conventional brake lever and the handlebar, coupled with the requirement for an operator to squeeze the brake lever toward the handlebar in order to actuate the brakes, creates an inherent operating difficulty for operators having a smaller than average hand size. An operator having a smaller than average hand often must grasp the brake lever with the tips of his fingers, resulting in a marginal capability for squeezing the brake lever with sufficient force to effect optimum brake actuation.
Another disadvantage of the conventional brake lever assembly is related to the effect of momentum on the operator's body. The conventional brake lever is usually located slightly forward of the handlebar grips. During a braking action, as the motorcycle slows down, the forward momentum of the operator's body tends to keep him moving in the forward direction. In order to operate the conventional brake lever, the operator must squeeze the brake lever toward the handlebar thus moving the brake lever in a rearward direction. To accomplish this action, the operator must overcome the restoring force of the spring in the brake lever assembly and his own forward momentum which tends to throw him in a direction opposite to the direction which he is trying to apply a force. During non-emergency conditions, the brakes are usually applied in a smooth and gentle manner and the effect of momentum on the operator's body has a relatively small effect on the operator's ability to operate the brakes in an optimum manner. However, during emergency conditions, the brakes are applied abruptly and the momentum tends to throw the operator's body forward. During these emergency conditions the operator must apply force in a rearward direction while being thrown in a forward direction. Unless the operator has sufficient manual strength his hand may be thrown off the brake lever, possibly causing an accident
In addition, the conventional brake lever assembly must be carefully located on the handlebar in order to enable an operator to reach both the brake lever and the throttle grip. This requirement creates limitations on the overall handlebar design.
Other disadvantages of the conventional brake lever assembly are related to the exposed nature of the conventional assembly. In the case of a major accident the exposed brake lever can act as a protuberance which can injure both the motorcycle operator and pedestrians who may be in the area. In the case of a minor accident, in which the motorcycle falls over, the brake lever can easily be bent or broken, resulting in a loss of braking capability.